package leetcode;

import javax.swing.tree.TreeNode;

/**
 * 修剪二叉树
 */
public class Solution23 {
    public TreeNode trimBST(TreeNode root, int low, int high) {
        if(root == null){
            return null;
        }

        //不在题目的区间范围内
        if(root.val < low){
            return trimBST(root.right , low , high);
        }
        if(root.val > high){
            return trimBST(root.left , low , high);
        }

        //在题目的区间范围内
        root.left = trimBST(root.left , low , high);
        root.right = trimBST(root.right , low , high);
        return root;
    }
}
